package xyz.zichengdulin.filter;

import jakarta.servlet.*;
import jakarta.servlet.annotation.WebFilter;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;
import lombok.extern.slf4j.Slf4j;
import xyz.zichengdulin.utils.JwtUtils;

import java.io.IOException;

@WebFilter(urlPatterns = "/*")
@Slf4j
public class TokenFilter implements Filter {

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        //HttpServletRequest继承servletRequest-----向下转型
        HttpServletRequest request = (HttpServletRequest) servletRequest;
        HttpServletResponse response = (HttpServletResponse) servletResponse;

        //1.获取到请求路径
        String requestURI = request.getRequestURI();    //  /emp/login

        //2.判断是否是登录请求，如果是包含 /login 的登录请求，则放行
        if (requestURI.contains("/login")) {
            log.info("登录请求，放行");
            filterChain.doFilter(request, response);
            return;
        }

        //3.获取请求头中的 token
        String token = request.getHeader("token");

        //4.判断 token 是否存在，如果不存在，说明用户没有登录，返回错误信息(响应401状态码)
        if (token == null || token.isEmpty()) {
            log.info("令牌为空，响应401");
            response.setStatus(401);
            return;
        }

        //5.如果token存在，校验令牌，如果校验不通过，则返回错误信息(响应401状态码)
        try {
            JwtUtils.parseToken(token);
        } catch (Exception e) {
            log.info("令牌非法，响应401");
            response.setStatus(401);
            return;
        }

        //6.令牌校验通过，放行
        log.info("令牌校验通过，放行");
        filterChain.doFilter(request, response);
    }

}
